Camp Pendleton Marines led by Maj. Gen. Charles “Mark” Gurganus relinquished command of U.S. and international troops in southwestern Afghanistan Thursday.

The handoff to East Coast Marine commanders capped a yearlong tour marked by a steep drawdown of troops, a spike in “insider attacks” by Afghan security allies and a catastrophic attack on the regional headquarters base.

Maj. Gen. W. Lee Miller and the 2nd Marine Expeditionary Force (Forward) took command in a ceremony at Camp Leatherneck, the main NATO and Marine base in southwestern Afghanistan for the U.S.-led International Security Assistance Force.

During the ceremony, Gurganus described the tour as a “year of complexity, challenges, and hard and good times,” that was sustained by the strength of the “confidence, courage and trust,” among Afghan and coalition troops, according to a Marine Corps release.

Army Lt. Gen. James Terry, second in charge of U.S. Forces Afghanistan, said: “Today, Afghans lead 80 percent of combat missions,” which he characterized as a “remarkable” turnaround.

“This shows what a coalition can get done. The idea of ANSF (Afghan National Security Forces) leading missions was just that, an idea. Now, it’s a reality,” said Terry, who is also commanding general of the coalition's Joint Command.

Local Marines will continue to serve in the supporting force of about 7,000, but the last command staff members from the 1st Marine Expeditionary Force (Forward) are expected to return to San Diego County Saturday.

Among those who recently returned was the air wing commanding general, Maj. Gen. Gregg Sturdevant, of the 3rd Marine Aircraft Wing headquartered at Marine Corps Air Station Miramar. Brig. Gen. John Broadmeadow, who is slated Friday to become deputy commanding general of the 1st Marine Expeditionary Force at Camp Pendleton, led the logistics element. Maj. Gen. David Berger, now head of the Marine combat center at Twentynine Palms, led Marine ground forces.

During their yearlong tour in southwestern Afghanistan, the NATO campaign shifted from leading counterinsurgency operations to working in small teams advising Afghan security forces.

The 1st Marine Expeditionary Force (Forward) also oversaw the pullout of more than 10,000 Marines stationed in Helmand and Nimruz provinces, and a dwindling number of other coalition troops. Out of 193 coalition bases in the region, 148 were closed or transferred last year to Afghan control.

The U.S. drawdown coincided with the fielding last year in southwestern Afghanistan of a fourth brigade of Afghan soldiers in the 215th Corps and increasing autonomy for local army and police units.

Among other developments: fatal attacks against coalition troops by Afghan national forces jumped nationwide in 2012 to 61, from 35 in 2011, according to NATO statistics.

The most destructive attack of the war unfolded on the night of Sept. 14, when 15 heavily armed insurgents infiltrated the flight line at Camp Bastion, the British-run side of the base adjoining Camp Leatherneck. A fleet of Harrier AV-8B vertical landing jets was destroyed, resulting in more than $200 million in damages, and two Marines were killed.

Coalition forces on the flight line, most of them from the 3rd Marine Aircraft Wing who deployed from San Diego County and Yuma, killed all the insurgents but one, who was captured and interrogated.

No one was fired or removed from command because of the attack, Gurganus said. Results of any command investigations that may have been conducted into the failure to protect the 1,600-acre base and its population of more than 10,000 have not been released.

Gurganus took command in March from then-Maj. Gen. John Toolan Jr., the three-star general who now leads the Marine force headquartered at Camp Pendleton. Gurganus told U-T San Diego in February that he is awaiting his next assignment from the Commandant of the Marine Corps. He is expected to receive a third star.

U.S. Marines began deploying in large number to southwestern Afghanistan in 2009, when a brigade of about 11,000 led by then-Brig. Gen. Larry Nicholson joined British troops trying to regain ground lost to the Taliban insurgency.

Most of the “surge” of U.S. troops sent to Afghanistan the next year went to southwestern Afghanistan and Helmand province, where a doubled-up force of Marines fought alongside about 10,000 British and other coalition troops in the deadliest region of the country.

At the peak some 100,000 U.S. troops were deployed to Afghanistan. President Barack Obama announced in February that roughly half the remaining 68,000 would withdraw within a year. The U.S. war campaign in Afghanistan is scheduled to end by late 2014.

CORRECTION: An earlier version of this story incorrectly referred to Army Lt. Gen. James Terry as second in command of the International Security Assistance Force in Afghanistan. That position is held by British Lt. Gen. Nick Carter.